Fuel injector



J. H. HQLLowAY FUEL INJECTOR Mud* 9 1948 J. H. HoLLowAY 2,437,529

` FUEL INJEGTOR Filed June 23, 1943 4 Sheets-Sheet 2 March 9, l948- J. H. HoLLowAY FUEL INJECTOR l Filed June 23, I`L943 4 Sheets-Sheet 5 Patented Mar.. 19, 1948 FUEL INJECTOB John H. Holloway, Green Bay, Wis., assignor to Northwest Engineering Company, Green Bay, Wis., a. corporation of Wisconsin Application June 23, 1943, Serial No. 491,892

4 Claims. (Cl. 103-41) The invention relates to fuel injectors for internal combustion engines and more particularly to the so-called unit injector in which the atomizer or sprayer is substantially directly connected With the discharge of the pump.

One of the objects of the invention is to improve the arrangement of the injector parts, so that the pump plunger and its barrel are of relatively short length and disposed at the upper end of the head of the engine while the sprayer is at the 4bottom of the head and connected with the pump barrel by a small or capillary passage, so that the clearance volume of the pump is not increased over former structures and themetering pump structure is greatly simpliiied and less special material need be used.

A further object of the invention is to improve the metering pump to permit changing in the timing of the injection with means for accurately adjusting the timing of individual injectors.

A further object of the invention is to provide for the drive of the pump plunger from a pair of cam operated levers with means for equalizing the thrusts on the plunger from said levers.

A further object of the invention is to provide Fig. ll is a detailed horizontal sectional View a simple and effective kpump discharge valve mechanism.

A further object is to improve the by-pass control mechanism for the indector.

The invention further consists in the several features hereinafter set forth and more particularly dened by claims at the conclusion hereof. T

In the drawings:

Fig. 1 is a vertical sectional view through a device embodying the invention taken on the line l-l of Fis. 2;

Fig` 2 is a horizontal sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 2;

Fis. 4 is a vertical sectional view taken on the line 4-4 of Fig. 2;

Fig. 5 is a detailed horizontal sectional view taken on the line 5 5 of Fig. 4;

Fig. 6 is a detailed horizontal sectional view taken on the line 6 6 of Fig. 4:

Fig. 7 is an enlarged vertical sectional view of the discharge end of the injector;

Fig. 8 is a detailed side elevation view of the discharge valve spring seat member;

Fig. 9 is a plan view of the seat member shown in Fis. 8:

Fig. 10 is a detailed horizontal sectional view through the spray nozzle:

Fig. 12 is a detailed horizontal sectional view taken 0n the line I2--l 2 of Fig. 3.

Referring to the drawings, the numeral I5 designates portions of e. cylinder head of an internal combustion engine and I6 an injector mounting' sleeve which has threaded engagement at l with the lower wall of the head and ring sealed engagement at I8 with the upper wall of the head. An injector mounting plate I9 also forms a part of the cylinder head structure and is provided with a bore 20 in which a tubular nut 2l is rotatably mounted, said nut having a gear 22 secured thereto meshing with a manually rotata-ble gear 23 journalled in the head part I9 and socketed to engage with a manually operable turning wrench 24.

The fuel injector includes a body member 25 and a casing member 26 which have threaded engagement with each other at 21 to form a nous..

ing and are locked in this engagement by a lock nut 28 and sealed against fuel leakage by a suitable compressible sealing ring 29. The member 26 is threaded at its lower end 30 to receive the sprayer clamping nut 3|.

The casing member 26 is tubular, is threaded on the outside at 32 to engage the threads of the nut 2|, has a pump barrel receiving cylindrical recess 33 in its upper end, a discharge passage 34 in itslower end and a bore 35 connecting said recess and passage and filled by a tube 36 having a small bore or capillary passage'31 formed therein.

A pump barrel 38 seats on the bottom of the recess 33 and is shouldered at its upper end 39 to receive a ilange forming ring 40 whose outer top portion abuts an annular clamping shoulder 4I formed on lthe body member. With this arrangement when the housing parts 25 and 26 are screwed together, the barrel 38 and ring 40 are clamped between them. Fixed positioning of the barrel relative to the body member 25 is obtained by a removable pin 42 connecting the barrel 38 to the ring and a. key connection between said ring and body formed by a vertical slot 43 in the ring engaged by the inner pin end of a bolt 44 mounted in the body 25. A fuel impact wear sleeve 45 is mounted in the recess 33 between its side wall andthe barrel 38 from which it is spaced so as to provide an annular fuel receiving space 46 including the tapered wall upper portion of the member 26. The barrel has an inlet port 41 and a relief port 48 longitudinally spaced therefrom.

A metering pump plunger 49 is mounted to reciprocate in the bore` of the barrel and has a control edge 55 at its outer or lower end adapted to cooperate with the port 41 to control the be-l Acommunicates with the pump chamber through a longitudinal bore 55 entering the front end of the plunger and connected with said groove by a cross bore 54. The control edge 55 is formed to change the time of the beginning of inJection with the amount of fuel injected. Thus injection will begin earlier for a heavier or full load charge than for a light or half load charge. The control edge 52 is formed to terminate the iniection after .the desired charge of fuel has been delivered. The particular timing and the amount of the charge is determinedy by the angular position of the plunger 49 relative to the ports 41 and 48 as different portions of said control edges 55 and 52 cooperate with said ports in different angular positions of the plungers. There are oppositely disposed sets of control edges 55 and 52, so that one set may be used after the other wears down so as to provide eilicient metering. Other porting arrangements may be used with the general arrangement of parts herein described.

The plunger 49 may be reciprocated by any suitable engine controlled drive mechanism but is preferably moved downwardly by a pair ofl spaced engine driven cams 55 each engaging a` roller 55 of a tappet lever 51 pivotally mounted on the shaft 55 carried by the body member 25 and having its inner end 59 engaging a half ball 55 seated in a spherically recessed block 5| mounted in a recess 52, formed in the flanged bottom 53 of a spring connector member 54, the flanged upper end 55 of the plunger iltting in and seating on said flanged bottom 59. The connector member 54 is in the form of a tube slidably mounted in a bore 55 in the body 25 and provided with diametrically disposed clearance slots 51 for the levers 51. The upper end ol.' the tube 54 has a spring seat collar mounted thereon and secured against release by a locking ring 59 engaging in an annular groove 15 in said tube. Plunger return springs 1| and 12 are interposed between the top of the body 25 and the collar 55 and act to hold the lower end of said tube, the block 5|. and the bearing member 55 in operative association with the levers 51 whose other ends are at the same time held .against their operating cams 55. With this arrangement the cams 55, whose shafts 55' are suitably driven from the crank shaft of the engine through gearing connections (not shown), act on the levers 51 to swing them downwardly and thus move the pump plunger 49 downwardly on its injection stroke and then allow the plunger to be returned or moved upwardly by the springs 1| and 12.

For shifting the angular position of the plunger 49, it is provided with a cylindrical upper portion 13 on which a gear 14 is non-rotatably slidably mounted as by ensgins a ilat on said portion (see Fig. 12) and which gear meshes with a shiftable segmental gear 15 whose sleeve-like hub 15 is mounted to oscillate on a shaft 11 vertically supported intermediate its ends in the body 25. Angular movement of the hub 15 is limited by a stop pin 15 carried by the body and extending into an arcuate slot 19 in said hub.

The hub 15 has an operating arm 55 mounted to rotate thereon between a shoulder 5| and a washer 52 secured in position by a nut 83 ensa9- ing the upper reduced threaded end of the shaft 11. This arm is adapted to be secured in different angular positions relative to the sleeve 15 by means of a pair of oppositely disposed set screws 84 carried by said arm and adapted to engage oppositely disposed stop surfaces 85 on the sleeve hub 15 formed by one of the sides of slots 85 in said hub. Thus by screwing in on one of the set screws 54 and loosening up on the other, the hub 15 is shifted angularly relative .to the operating arm 55 and the gear 14 turned slightly to determine the exact position of the plunger 49 relative to the inlet -port 41. The screws 84 are lockedin adjusted position by lock nuts 54.

The arm 55 is removably connected to a longitudinally movable control rod Il by a recessed thrust washer 5| at the other and held in the body 25 by a split ring 92 engaging in a groove 93 in said body. The plunger slides down into position in the barrel and the gear 14 in assembling the device.

For supplying fuel to the pump barrel means are provided for continuously circulating fuel through the space 45 and shown more particularly in Figs. 4, 5, and 6. In Fig. 5 there are drilled fuel supply passages 94 and 94 intersecting opposite sides of a vertically disposed bore 95 in the part I9, one of these passages being connected with the discharge' side of a fuel circulating pump (not shown) and the other with the suction side of such pump. The lower end of the shaft l1 removably fits in the bore 95 and has a vertically extending bore 95 divided at its lower end by a partition member 91 into two lateral passages 98 and 99, the passage 98 communicating with an air chamber |55 formed by the upper end of said bore 95. The bore 95 is sealed against fuel leakage by a conical rubberlike sealing ring |5| yieldingly held against the shaft 11 and a seat |52 at the upper end of the bore by a follower ring |53 and a spring |54 uiterposed between said ring |53 and the part of the body 42 in which the intermediate portion of the shaft 11 is mounted'and secured. The passage 95 is connected at its lower end by a hole |55 in shaft 11 with the inlet passage 94 and at its upper end by a hole |55 in said shaft with a chamber |51 in the member25.

The passage 99 is connected at its lower end by a hole |58 in the shaft 11 with the outlet passage 94' and at its upperend by a hole |59 in said shaft with a chamber i5 in the member 25. Each chamber |51 and ||5 is closed at its outer end by a screw plug and at its inner end has a strainer I2 mounted therein and secured in position by a spring ||3 interposed between said strainer and plug. The inner end of the chamber |51 is connected to the chamber by al passage ||4, and the inner end of the chamber ||5 is connected to the chamber 45 by a passage H5. As a result of this construction fuel 'from the supply line enters the chamber from the passage H4, and

anemona Itis to be noted that sincethe shalt 1'I is xed to the body member 42, it is removable with said member when the casing 26 -of said injector is unscrewed from the nut 20.

The pump discharge valve and spray nozzle or sprayer may be oi?v any suitable construction, but the speciilc -i'orm shown in detail in Fig. '7 is preferred. In this figure, the numeral I I6 designates a Valve seat disk abutting the lower end of the casing 26 and ||1 a nozzle member whose upper anged end ||8 abuts against the disk, these parts being secured in tight clamping engagement with each other and with the casingby the clamping nut 3| having the inwardly extending flange ||9.

The'nozzle member I I1 has a passage formed by concentric bores |20 and |2| extending from its upper end down to its tip |22 where the bore |2I is intersected by a plurality of radially disposed spray openings |23 drilled in said tip. The bores |20 and |2| form a conieally walled shoulder |24 on which the lower conical end of a spring seat and valve stop member |25 is mounted, said member having intersecting inclined grooves |26 out or formed in its lower end to provide communication between the bores |29 and I2 I.

A discharge valve |21 controls the flow of metered fuel through the passage |28 in the disk I6 which communicates with the passage 34 in the casing member 26 and is preferably in the form of a flat faced disk |29 seating on the flat seat disk |I6 and which may have a spring guide and stop portion |30 that cooperates with the member |25 to limit the lift of the valve to a small amount, a spring |3| being interposed between the head of said valve and the member |25 to normally hold said valve in closed position.

With this construction the injector is mounted on the engine by inserting thecasing 26 down through the nut 2| and into the tube I6 and the shaft 11 into the bore 95, which brings the pin 88 in line with the notch in the block 81, and then turning the nut 2| through the gears 22 and 23 to screw the casing 26 into said nut and bring the lower end of the nozzle clamping nut 3| into sealing engagement with a gasket IIB seated at the lower` end of tube I6 to provide a gas-tight joint between the lower end of the injector and the head. When the fuel circulating pump is started, the fuel will be delivered to the space 46 adjacent the ports 41 and 48 in the barrel, and then when the engine is started, the rotating cams 55 and the springs 1| and 12 will cause the reciprocation of the plunger 49' in cy- `clic synchronism with the engine. On its down stroke the plunger 49 which on its suction stroke has uncovered the port 41 to admit a charge of fuel into the barrel 38 forces this fuel from the lower end of the barrel through the clearance passages 31, 34, and |28 past the loaded discharge valve |21 through the bores |20 and |2| and out through the spray passages |23 in a nely atomized spray. The amount of the sprayed charge will depend upon the annular setting of the plunger 49 relative to the barrel 38 to cause opening up of the by-pass port 48 sooner` or later in the expressing stroke of the plunger. The control surfaces permit the adjustment of the plunger from a no-delivery to a full delivery position.

With this arrangement the metering parts of the pump are formed as a small compact unit in which diil'icultles due to bending and wrapping of the plunger have been substantially eliminated without interfering with thel efilcient metering and delivery of the fuel to and through the sprayer at the lower end of the injector. By the term "capillary as applied to the passage 31 I mean a' lpassage ywith a diameter between one--thirtysecond and one-sixteenth of an inch, so that while this tube may be made long in case of a relatively deep engine head, the over-all clearance of this passage is very small, so that the volumetric efliciency of the pump is not impaired. The timing of the beginning of injection may be accurately determined throughthe setting of the gears l14 and 16, and the gear 15 is prevented by the stop 18 from being turned beyond the desired limits of its adjustment.l The half ball bearing 60 seated in the block 6| equalizes the thrusts from the levers 69 and permits eillcient drive of the pump plunger 49 even though one ofhthe levers 59 may lag slightly relative to the ot er.

I desire it to be understood that this invention is not to be limited to the speciiic form or arrangement of parts above described except only in so far as such limitations have been included in the claims.

What I claim as my invention is:

1. In a fuel injector, the combination of a casing member, a pump barrel with a plunger working therein mounted in said member, a body member secured to said casing member, a pair of opposltely disposed plunger operating levers carried by said body member for moving the plunger in its delivery stroke, a thrust member having a, spherically curved bearing surface connected with said plunger and a at surface engaged by said levers, and spring means mounted -on said body member and operatively connected to said thrust member to move the plunger on its return stroke.

2. In a fuel injector, the combination of a casing member, a pump barrel with a plunger working therein mounted in said member, a body mem- 3. In a fuel injector, the combination of a'casing member, a valve controlled passage at one end of the casing, a pump barrel with a plunger working therein in the other end of said. member, a body member secured to the barrel receiving end of said casing member and having a bore alined with said plunger and opposltely disposed slots communicating with said bore, said plunger hav- .in-g a anged outer end, a sleeve member slidably mounted in said bore and having an inwardly extending ange at its lower end on which the ilanged end of said plunger seats, a. bearing block mounted in said sleeve and engaging the flanged end of said plunger and having a spherically curved recess, a half ball seated in said recess, opposltely disposed 'cam operated levers pivotally mounted in said slots in said body member and projecting into the bore in said sleeve and engaging the flat side of said half bali, and spring means constantly urging said sleeve member to a bearing contact with said bearing block.

4. In a fuel injector, the combination of a housing having a pump barrel mounted therein,

' 7 a pump plunger working in said barrel. laid plunger having a control edge and said barrel having a port cooperatinz with said control edge,`means for adjusting the angular position of the plunger relative to said port including an oscillatory member. a shaft supported by said housing on which said oscillatory member is mounted, said REFERENCES CITED The following references are of record in the 111e ot this patent:

Number UNITED STATES PATENTS Name Date Ritz Jan. 28. 1934 Mock Mar. 27, 1934 Ritz Nov. 27, 1934 Bernard Oct. 8, 1935 Murphy June 8. 1937 Fielden Oct. 26, 1937 Trapp May 24, 1938 Truxell Jan. 24. 1939 Truxell Jan. 24, 1939 Smith Dec. 18, 1939 Edwards Dec. 26, 1939 Edwards Jan. 30, 1940 Holloway et a1 Oct. 7, 1941 Murphy Feb. 3, 1942 Schweitzer Nov. 10, 1942 

